Agreed and I'd add that she didn't have any reason to doubt him since she found him killing homeless drug addicts instead of hanging out with the Countess. That doesn't seem like something her current love would do.

I totally thought this might happen as well since there are serious parallels between Holden/Her and Iris/Donnovan but then I suspected that since she is a doctor and had that monologue about vaccinations that she may try and do the opposite and cure them.